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RockShox XC28 spring upgrade

26K views 39 replies 18 participants last post by  hadley.michael 
#1 ·
I have the Guardian with the stock XC28 80mm fork. I came across a RockShox manual that recommends for my weight (195-200lbs) I should be running a firm spring as opposed to the factory medium spring.

http://cdn.sram.com/cdn/farfuture/w...coil_spring_chart_gen_0000000004149_rev_c.pdf

I found the spring kit at several outlets for about $23, not too bad.

Here are my questions:

1. Is the spring swap worth doing?

2. How difficult is this spring swap? Has anyone here had one of these apart?

3. Most of the firm springs I have found are 100mm. Will a 100mm spring work in my fork?

The fork is not doing a bad job for my type of riding. Mostly single track with lots of roots and an occasional short drop. I have the preload maxed out. If I can improve the performance for 23 bucks I'm all for it. What do you guys think?
 
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#12 ·
I got UPS today. Firm Spring~!

Product Photograph Font Household hardware Technology

First unscrew top knob which has preload adjustment.
after take it out, push down handle bar and take out top spring part.

and take bottom nut(A) with allen wrench.
Bicycle drivetrain part Bicycle part Bicycle accessory Groupset Crankset

Product Line Font Colorfulness Black


Bottom part(B) won't come out unless you hammer it(C) out.
Bicycle tire Bicycle wheel rim Bicycle part Bicycles--Equipment and supplies Bicycle accessory


Put some grease on new bottom part and put it back to the shock.
Put some grease on new top spring part and put it back to the shock.
It will push down bottom part so you can screw the bottom nut which is A in picture
and tight the preload adjustment knob.
that's it.:thumbsup:
It would take 20minutes.

and for someone like me.
Here is the picture shows how preload work.
Product Text Lens Photograph Line
 
#35 ·
I got UPS today. Firm Spring~!

View attachment 809638
First unscrew top knob which has preload adjustment.
after take it out, push down handle bar and take out top spring part.

and take bottom nut(A) with allen wrench.
View attachment 809639
View attachment 809644

Bottom part(B) won't come out unless you hammer it(C) out.
View attachment 809640

Put some grease on new bottom part and put it back to the shock.
Put some grease on new top spring part and put it back to the shock.
It will push down bottom part so you can screw the bottom nut which is A in picture
and tight the preload adjustment knob.
that's it.:thumbsup:
It would take 20minutes.

and for someone like me.
Here is the picture shows how preload work.
View attachment 809646
Is it necessary to get that rod out installing the heavier spring ? I can't get mine out , afraid I'm going to break something hammering on it.
 
#16 ·
I'm not a bike mechanic or an expert at working on forks, but I'm betting you can damage your bike by hammering on the fork while it's still attached to the bike. Especially while it's laying upside down on the garage floor. I would take the fork off the bike and work on it independently.
 
#23 ·
I was looking at the parts diagram for this shock and the only parts that are specified as being different between 80/100mm are the parts included in the spring kit. I may very well may be missing something here, but it looks like installing the 100mm spring kit may yield a 100mm fork. Admittedly I found it difficult to decipher the parts diagram/list, so I could be completely off base with this. I need to get off of my bum and just give it a shot.

Here is a link to the parts diagram I was referring to:

http://cdn.sram.com/cdn/farfuture/Q...lt/files/techdocs/2012_rockshox_spc_rev_c.pdf

The diagram and parts list are on pages 9 and 10. Take a look and see what you think.
 
#25 ·
So, would it be safe to assume that if you were to get the 80mm spring kit for an XC28 that was originally 100mm, it would reduce the travel (and, more importantly, the A2C distance?)

This is for an older bike, so I'd like to keep the A2C around 450, and the XC28 is 471, probably do-able, but under 450 would be better (running a Surly Instigator fork at 445 and its perfect right now)
 
#28 · (Edited)
What kind of grease do you use? And do you just smear it all over the springs? Im going to put an xtra firm in my xc28 tomorrow.

i took my spring out and it came off easy without removing to bottom piece. I didn't swap springs though because I don't have any grease. The stock spring was covered in grease. Looks like the stock spring on my bike is a dark blue color. Or maybe like a grey. Definetly not light blue like the extra form one I bought. But I can't really tell a difference visually by looking at the spring thickness. Figured it would be a significant difference but I don't see it.

When we talk about the color we are talking about the plastic piece at the top of the spring right?

So does that bottom piece make a difference. Would be really easy to just remove the spring and not mess with the bottom.
 
#31 ·
I want to make sure I've got this right. The SRAM diagram makes it look like there's two springs on the left and the pts list indicates spring/spacer and a spring shaft kit. SO does the spring shaft kit have a smaller spring or is it just a crappy diagram? Also which spring set tends to be light in grease? (cause my fork started sounding like a pogo stick.)
 
#32 ·
Hi. Did anyone tried to increase or decrease the spring size on this fork?

I bought this same fork with the 100mm travel spring to install in an old Trek 990 (originally w/ Rockshox Indy XC w/ 63mm travel). I'm afraid this will eventually damage the frame and wanted to decrease the fork travel w/ a 80mm spring.

Do I need any additional part to complete this change? What do I need to adjust / take out from the other leg of the fork?

I am still a complete noob with a very old bike, so I appreciate your help.
 
#34 ·
Trying to find info on this fork is quite difficult - I spent quite a few hours searching the internet and most of my results linked back to this thread and the SRAM parts document. I'll add my few cents worth to hopefully help anyone looking in the future.

The stock spring in the Guardian (1.0) fork did well for my weight and riding style for over 1000 miles. I weigh 255lbs and ride XC with rocky sections and some mild drops. But like anything else I own I thought the fork could use some modifications. I ordered the firm spring with 100mm travel to replace the medium 80mm spring in my fork. The replacement is stupid simple as noted in previous posts. I replaced both the spring and the lower rod. Took fifteen minutes due to distractions from the rambunctious kids in the house. Probably could be completed in five minutes! The stock spring did not have much grease at all on the coils so I coated the new spring before installing.

The travel is determined by a removable plastic spacer attached to the spring coil. The 80mm spring has a spacer that is 20mm longer than the 100mm spacer and stops travel sooner. A rider looking to increase travel from 80mm to 100mm for free could probably get away with trimming the spacer on the stock 80mm spring.

The oil volume listed on the SRAM document is the same for 80/100mm travel so I have not messed with anything on the right side.

The firm spring is just that - quite firm! I will be experimenting with the different combos of medium and firm springs as well as the 80mm/100mm spacers. My first observation is that with the firm spring I need almost zero preload adjustment on the fork. I had the preload cranked up quite a bit with the medium spring. With the firm spring in place I have a hard time compressing the fork much at all while static testing. I've yet to get a ride in on the firm spring with 100mm travel (again, those pesky kids!lol) but I'll report back when I get the chance.

Also, as a warning to anyone looking at increasing the travel to 100mm, I do believe I read in the warranty for Airborne that use of an increased travel fork voids said warranty. Not sure but just a heads up!
 
#36 ·
@JohnFL

i had some trouble as well. at first i tried using a screw driver placed on the edge of "c."
the screw driver slipped off of the edge and went into C were the treads are... this is what i was trying to avoid. so i tried using an allen key big enough to to stay out of the threads but small enough to get in there. lots of hammer and still no results. so since there was a replacement for everything i just said screw it.. got the screw driver again and steeled my reserve... it definitely wasn't just a few taps...i was going Happy Gilmore at this point ... tap taparo... why wont you tap out... come out... you don't want to be in there... get the hell out of there! and finally that greasy bastard came free and plopped out onto the floor.

got everything inside easy enough. there was one part that came with the spring kit... a rubber cylinder with 2 groves... no idea what it was for... no one mentioned it in any videos or pictures so i figured i shouldn't worry... still bugs me... anyone know what it is for?

also... anyone have any tips on how to properly "tap" this guy out. im sure there is a proper tool... and even without a tool designed for this sole purpose.. there has to be a better way than what i did. more info on proper techniques would probably help with anxiety when banging on expensive toys.

my only tip which is probably just common sense... i removed the front wheel... i didn't want to be swinging hammers and bashing the brake's disc
 
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